[Acid volatile sulfide and heavy metals biotoxicity in a municipal polluted river]

The surface layer of sediment and overlying water samples of Foshan Waterway, a typical municipal polluted river in Pearl River Delta, have been sampled and analyzed. The analytical items of sediment and overlying water include AVS, Eh, SEM(Pb), SEM(Cd), SEM(Cu), SEM(Zn), SEM(Ni), SEM(Cr), and Eh, DO, respectively. The benthic macroinvertebrate investigation has been done at the same time in the same place. Combing the results above, the relationship between AVS and heavy metals biotoxicity in Foshan waterway has been discussed. The main object is to examine if the SEM-AVS criterion is valid in judging the biotoxicity of heavy metals in the heavily polluted river. The range of AVS is from 0.339 micromol/g to 69.579 micromol/g, with the average of 20.283 micromol/g. The maximum sigmaSEM5 (Sum of SEM(PB), SEM(Cd), SEM(Cu), SEM(Zn), SEM(Ni)) is 23.067 micromol/g, while the minimum is 1.062 micromol/g. Both the species and quantity of benthic macroinvertebrate are little, and most of them belong to pollution bearable species, with Limnodrilus sp. as dominative species. There are 9 sampling stations where the sigmaSEM5-AVS are below zero, and the analytical results of Non-matric multi-dimentional scaling (MDS) indicate the benthic community structure of 7 sampling stations among them are similar. It means that the heavy metals biotoxicity in the heavily polluted river has close relationship with the value of SEM-AVS. It also proves that heavy metals biotoxicity in sediment is complicated, which can't be explained by SEM-AVS completely.